• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.2 no.1
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• pp.69-75
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• 2004

DORT and ORIGEN2 code were used for calculation of neutron flux and inventory in reactor pressure vessel(RPV) of Kori unit-1, To calculate neutron flux using DORT code, the reactor was divided into 94 mesh from the center of core to RPV and from 0 to 45 degree along the azimuth. The cross-sections of main nuclides were recalculated using neutron flux in the RPV region. The results showed that 95% of the total activity in RPV came from the nuclides of $^{55}$ Fe, $^{60}$ Co, $^{59}$ Ni and $^{63}$ Ni. And the total activity with cooling of more than 50 years after decommissioning was no more than 0.2% of at the time of shutdown. Considering the weight of RPV is 210 tons, the initial total activity of RPV reached 5.25${\times}$10$^{6}$ GBq. To verify results of ORIGEN2 calculation, comparison between calculated and measured value at RPV of Kori unit-1 was peformed. The comparison results showed a good agreement.

• Biomolecules & Therapeutics
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• v.16 no.4
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• pp.385-393
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• 2008

As an attempt to search for bioactive natural products exerting anti-inflammatory activity, we evaluated the effects of the methanol extract of Polytrichum commune Hedw (PCM) (Polytrichaceae) on lipopolysaccharide (LPS)-induced nitric oxide (NO), prostaglandin $E_2$ ($PGE_2$) and pro-inflammatory cytokines release in murine macrophage cell line RAW 264.7. PCM potently inhibits the production of NO, $PGE_2$, tumor necrosis factor (TNF)-$\alpha$ and interleukin (IL)-6. Consistent with these results, PCM also concentration-dependently inhibited LPS-induced inducible NO synthase (iNOS) and cyclooxygase (COX)-2 at the protein levels, and iNOS, COX-2, TNF-$\alpha$ and IL-6 at the mRNA levels without an appreciable cytotoxic effect on RAW 264.7 macrophag cells. Furthermore, PCM inhibited LPS-induced nuclear factor-kappa B (NF-$\kappa$B) activation as determined by NF-$\kappa$B reporter gene assay, and this inhibition was associated with a decrease in the nuclear translocation of p65 and p50 NF-$\kappa$B. Taken together, these results suggest that PCM may play an anti-inflammatory role in LPS-stimulated RAW 264.7 macrophages through the inhibitory regulation of iNOS, COX-2, TNF-$\alpha$ and IL-6 via NF-$\kappa$B inactivation.

• Molecular & Cellular Toxicology
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• v.1 no.4
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• pp.230-236
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• 2005

Formaldehyde is a common environmental contaminant found in tobacco smoke, paint, garments, diesel and exhaust, and medical and industrial products. Formaldehyde has been considered to be potentially carcinogenic, making it a subject of major environmental concern. However, only a little information on the mechanism of immunological sensitization and asthma by this compound has been known. So, we performed with Jurkat cell line, a human T lymphocyte, to assess the induction of DNA damage and to identify the DEGs related to immune response or toxicity by formaldehyde. In this study, we investigated the induction of DNA single strand breaks by formaldehyde using single cell gel electrophoresis assay (comet assay). And we compared gene expression between control and formaldehyde treatment to identify genes that are specifically or predominantly expressed by employing annealing control primer (ACP)-based $GeneFishing^{TM}$ method. The cytotoxicity ($IC_{30}$) of formaldehyde was determined above the 0.65 mM in Jurkat cell in 48 h treatment. Based on the $IC_{30}$ value from cytotoxicity test, we performed the comet assay in this concentration. From these results, 0.65 mM of formaldehyde was not revealed significant DNA damages in the absence of S-9 metabolic activation system. And the one differentially expressed gene (DEG) of formaldehyde was identified to zinc finger protein 292 using $GeneFishing^{TM}$ method. Through further investigation, we will identify more meaningful and useful DEGs on formaldehyde, and then can get the information on the associated mechanism and pathway with immune response or other toxicity by formaldehyde exposure.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.198-198
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• 2011

Organocatalysis is a relatively new and popular area within the field of chiral molecule synthesis. It is one of the main branches of enantioselective synthesis with enzymatic and organometallic catalysis. In recent years, immense high quality studies on catalysis by chiral secondary amines were reported. These progresses instantly led to different organocatalytic activation concepts, so thousands of researchers from academia and the chemical industry are currently involved in this field and new ideas, new approaches, and creative thinking have been rapidly emerged. Organocatalysts, some of which are natural products, appear to solve the problems of metal catalysts. Compared to metal-based catalysis, they have many advantages including savings in cost, time, and energy, easier experimental procedure, and reduction of chemical waste. These benefits originate from the following factors. First, organocatalysts are generally stable in oxygen and water in the atmosphere, there is no need for special equipments or experimental techniques to operate under anhydrous or anaerobic conditions. Second, organic reagents are naturally available from biological materials as single enantiomers that they are easy and cheap to prepare which makes them suitable for small-scale to industrial-scale reactions. Third, in terms of safety related catalysis, small organic molecules are non-toxic and environmentally friendly. Therefore, the purpose of this research is to develop novel synthetic methods and design for various organocatalyst. Furthermore, it is expected that these organocatalysts can be applied to a variety of asymmetric reactions and study the transition state of these reactions using a metal sulface. Here, we report the synthesis of unprecedented organocatalysts, proline and pyrrolidine derivatives with quaternary carbon center.

• Korean Journal of Animal Reproduction
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• v.17 no.3
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• pp.183-191
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• 1993

These experiments were carried out to investigate whether the enzyme is involved in zona hardening during normal activatin of the oocytes by sperm, and demonstrate peroxidase activity during in vitro fertilization of oocytes treated with peroxidase inhibitors(250 $\mu$M phenylhydrazine, 28mM sodium sulfite, 350mM glycine ethyl ester and 50mM sodium azide) and tyrosine analogue(12.5mM tyramine). Also, zona soluble properties of the ovarian oocytes incubated for 0, 5, 10 and 15 hr in the presence of pheylhydrazine or tyramine were studied by using $\alpha$-chymotrypsin. The results obtained from these experiments were summarized as follows ; 1. The rates of fertilizatin in control oocytes and oocytes treated with phenylhydrazine or tyramine were 69.8%, 62.3% and 88.2%, respectively. However in vitro fertilization in oocytes treated with three different peroxidase inhibitors, sodium sulfite, glycine ethyl ester and sodium azide, were not induced. The oocytes treated with phenylhydrazine had no significant effect on in vitro fertilization rate as compared to control. However there was a significantly different in fertilization between tyramine treated group and control group(P<0.01). 2. The zona solubility(t50) of control and fertilized oocytes in culture treated with phenylhydrazine or tyramine were 30.7, 26.0 and 16.3 min., respectively. Phenylhydrazine treated group and tyramine treated group had effect on inhibition of zona hardening as compared to control group. These results suggest that ovoperoxidase is involved in zona hardening during normal activation of the oocytes by sperm. 3. t50 of control oocytes and ovarian oocytes treated with phenylhydrazine or tyramine for 5, 10 and 15 hr in vitro were 14.0, 26.2 and 32.0 min., 14.5, 26.9 and 30.2 min., and 14.0, 24.3 and 31.2 min., respectively. These results suggest that zona hardening in ovarian oocytes matured for various times in vitro cannot be inhibited by peroxidase inhibitors and tyrosine analogue, that the spontaneous zona hardening incultured ovarian oocytes is not caused by the secretory products of cortical granules released during the cortical reaction, ovoperoxidase.

• Journal of Pharmaceutical Investigation
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• v.28 no.2
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• pp.121-126
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• 1998

The solubility and physicochemical stability of caroverine hydrochloride (CRV), an antispasmodic, in buffered aqueous solutions were studied using a reverse phase high performance liquid chromatography. The solubilty of the drug at pH 2.76-5.40 was similar at the range 31.9-36.2 mg/ml $(34^{circ}C)$, but, at the pH higher than 6.0, markedly decreased. The use of polyethylene glycol 400 as a cosolvent did not increase the solubility at any compositions examined. Moreover. increasing molar concentration of aqueous phosphate buffer from 0 to 0.5 M remarkably decreased the solubility. The degradation of CRY followed the apparent first-order kinetics. The degradation was accelerated with decreasing pH and increasing storage temperature. The half-lives for the degradation of CRY (1.0 mg/ml) at pH 1.28. 4.01 and 5.93 $(45^{\circ}C)$ were 2.8, 31.4 and 124 hr. respectively. The pHs of incubated solutions were to some extent lowered perhaps due to the formation of acidic degradation products. The addition of disodium edetate (0.01%) to the CRY solution (pH 4.95) retarded 2.5 times the degradation rate at $45^{\circ}C$, but the use of sodium bisulfite (0.1%) accelerated 2.9 times the rate. The activation energy for the CRY solution (20 mg/ml. pH 5.4) containing 0.01% EDTA was calculated to be 5.98 kcal/mole. When the solution was stored under nitrogen displacement in ampoule, there was no significant degradation even after 3 months at $40^{\circ}C$, indicating that protection from oxidation by air (oxygen) is essential for the complete stabilization of CRY solution.

• Applied Biological Chemistry
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• v.3
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• pp.1-7
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• 1962

In order to study the rate control step in the protein metabolic course of the chlorophyll formation, the transaminase activities which are obtained freely in the extracts of cotyledons of germinating peas at the light and the dark places, are measured in Beckman mopel D.U, spectrophoto meter at 490 mu. In this case, of two enzymatic reaction products; oxalacetic acid and pyruvic acid, the former is converted to pyruvic acid by aniline citrate and after each pyruvate phenyl hydrazones are extracted by toluenes: when this is treated with strong alcoholic alkali, a colored hydrazone is formed and it is measured by above apparatus. The estimated G.O.T. and G.P.T. in the germinated cotyledons at dark and light places considerably differ in their activities; G.O.T. and G.P.T. activities which are formed at the light are more increased than at the dark and also they differ in their rates through germination, though G.O.T. activity increment is smoothly but that of G.P.T. is more sharply, and they are considered to be directly affected to the chlorophyll formation and indirectly to the growth. G.O.T. and G.P.T. in each fractions of cell in the cotyledons should be formed by dissociation of zymogens in the microsomal fractions and it seems to promoted by light. In the formation of the chlorophyll, the protein metabolism occurred mainly in the microsomal fractions and the rate determining step is found at the point where the zymogene that is able to produce G.P.T. is activated, and this activation is promoted by light as noted above.

• Applied Microscopy
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• v.22 no.2
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• pp.46-65
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• 1992

In this study, we have made morphological and cytochemical observations to investigate the type of Golgi apparatus around the bile canaliculus. The animal (Wister, $220{\sim}250gm$) were divided into 4 groups; normal, hydrochol, colchicine and hydrochol-colchicine. The Golgi apparatus is classified into 16 different types from 4 different groups. In the normal group, we could observe 12 different types of the sixteen. Type I which showed convexed cisterns facing the bile canaliculi was most abundant of the types. In the hydrochol group, 14 types were observed. Type VII and type I showed convexed cisterns facing the bile canaliculus and were abundant. In the colchicine group, 11 different types were viewed and type XIV which showed intensely dilated cisterns without the polarity was predominant. In the hydrochol-colchicine group, we observed 3 different types. Type XIV clearly showed the highest percentage, although that type was less numerous in this group than in the colchicine group. In the hydrochol group, the Golgi apparatus showed a tendency to increase in numbers, while in the hydrochol-colchicine group the Golgi apparatus showed a tendency to decrease in numbers. The reactive products of thiamine pyrophosphatase and acid phosphatase were apparent over the distal Golgi cistern in the normal and hydrochol groups, but were decreased or not observed in the colchicine and hydrochol-colchicine groups. From the results, it is assumed that with the presence of the microtubule, Golgi cisterns are dilated with polarity after stimulation of secretion. Without the microtubule, the cistern becomes more intensely dilated and none polaric. Also the enzymes within the cisternal membrane become decreaed or absent and the Golgi apparatus decreases in numbers after activation of secretion.

• Applied Chemistry for Engineering
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• v.4 no.1
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• pp.94-102
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• 1993

The effects of temperature and of $Na_2O$ and $SiO_2$ contents on the crystallization of zeolite A were studied, by examining crystallization curves and particle size distributions of final products at various crystallization conditions. Crystallization process could be simulated adopting the assumptions of constant linear growth rate and equilibrium between amorphous solid phase and soluble species. Rate constants were determined by comparing the simulated crystallization curves with experimental data. Rate constant for linear growth increased with temperature and crystallization rate at different mole ratio of $Na_2O/H_2O$ correlated reasonably well with increase of soluble species. The rate constant of crystallization did not increase with increase in mole ratio of $Na_2O/H_2O$, but the rate of nuclei formation and the fraction of soluble species were enhanced. The rate constants for linear growth of zeolite A were determined as $0.07{\sim}0.24{\mu}m{\cdot}min^{-1}$ at these experimental conditions Apparent activation energy was estimated as $49kJ{\cdot}mol^{-1}$.

• Korean Journal of Food Science and Technology
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• v.3 no.3
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• pp.135-143
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• 1971

In order to find out the degree of mercury contamination of common foodstuffs a series of determination was carried out by a highly sensitive activation analysis and the following results were obtained. 1. Polished rice contained 0.050 ppm of mercury whereas rice bran had 0.095 ppm mercury which was found in other grain in lesser degree. 2. Vegetables and fruits also contained $0.035{\sim}0.190\;ppm$ of mercury with relatively small variations from sample except persimmon which had a considerably higher amount of mercury. 3. Soybean sprout contained an unexpectantly high amount of mercury. 4. Of the animal products chicken and egg contained more mercury than the meat.